The Biostatistics Core will provide statistical and data management support for each of the projects in the program. This support will include: 1) assistance in study design; 2) assistance in data entry; 3) writing SAS or other data entry and editing programs; 4) completion and presentation of analyses; 5) assistance in integrating statistical interpretation into scientific conclusions and reports; 6) development of new statistical techniques as needed; 7) documenting data files for ease of accessibility in the future; 8) archiving data files for long-term storage; and 9) presentation of statistical seminars to investigators.